Robots are commonly used in the manipulation of parts, often as a replacement for the manual manipulation of parts. For example, pick and place robots are often used in production processes, such as assembly lines, to transfer parts between machines, or to position parts relative to each other (e.g. parts in holders). The robots often operate at high speeds to allow large numbers of parts to be moved and positioned quickly, in order to enable high production rates. Dependent on the nature of the parts being moved and the particular movement, robots can often achieve cycle times of a fraction of a second. Tolerances on the positioning of the parts can be tight with the robot positioning the parts accurately over a large number of cycles.
In order to achieve a high accuracy, the robots typically comprise arms with a high degree of stiffness to reduce deformations when moving at high speed. The stiff arms generally have a relatively high mass such that powerful motors are required to move the arms at the high speeds that are desired. Larger motors and stiffer arms with lower masses, such as carbon fibre arms, can help to increase speeds. However, such robots are generally complex and expensive, and are often inefficient.